LONDON , England -LRB- CNN -RRB- -- London commuters crammed onto buses , scrambled for taxis , cycled or simply walked on Wednesday as a strike by Tube workers shut down most of the subway network .

Commuters queue for packed buses in London on Wednesday morning .

The strike began Tuesday at 7 p.m. -LRB- 2 p.m. ET -RRB- but the first full effects were felt during Wednesday 's morning commute . The strike was set to last for 48 hours with a normal service resuming Friday morning , according to Transport for London -LRB- TfL -RRB- , which runs the city 's transportation network .

The RMT trade union called the strike after talks with management over pay , job cuts , and disciplinary issues broke down .

`` RMT does n't resort to industrial action lightly , '' General Secretary Bob Crow said in a statement . `` The fact is that Tube workers have been driven into walking out today . ''

Transport Commissioner Peter Hardy said the talks had been making progress on all issues and he urged the RMT to return to the table .

`` The RMT leadership says we were close to a deal , '' Hardy said in a statement . `` If that is the case , then they should call off the strike , return to talks ... and resolve this issue without any more disruption to Londoners . ''

TfL was running extra buses and free shuttle services across the River Thames during the strike . Electronic travel cards used for the TfL network were temporarily being allowed on all train lines in greater London , it said .

While most services on the Tube were shut because of the strike , one line -- the Northern line -- was running normally and five others were running on a reduced schedule , TfL said .

`` It 's been really good , '' a girl on Oxford Street told CNN about her commute . `` The Northern line is running perfectly . ''

Still , some bus services were packed with commuters who normally ride the underground trains or who failed to find a taxi .

`` I think we 'd all like to strike for more money , but unfortunately we ca n't , '' said one woman at Oxford Circus , where the Tube is closed .

Others hit the pavement and walked .

`` It 's OK -- quite refreshing , '' said a man on Regent Street . He said he had just walked from Liverpool Street Station , a train station as well as a Tube stop that is more than 2.5 miles away .

The RMT represents about half of the 20,000 employees on the Tube , a TfL spokeswoman said . Other unions including Unite and TSSA represent the rest , she said , and were not on strike .

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London transport system crippled as Tube workers go on strike

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Normal service not due to resume until Friday morning

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Buses crammed with commuters ; many chose to cycle , walk to work

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RMT trade union called strike in dispute over pay , job cuts , disciplinary issues